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SportsterDoc,
If you're riding in very high temps, I'd recommend switching to a synthetic. The combination of high temps and an air cooled engine can be very tough on dino oil. Add to that the shear factor from the oil circulating through the transmission gears and you're asking a lot from a multigrade dino oil.
Several years ago I started doing oil analysis on my bikes and found that summer time riding temps ( up to 115F) were having a bad effect on my favorite multigrade dino oil. The viscosity was down to a straight 20 weight after only 2000 miles.
I ended up switching both bikes to synthetic oil. Subsequent oil analysis showed that it was holding up well beyond 3500 miles of summer time riding. Well worth the extra few bucks!
I use Shell Rotella T6 (5w-40) in both bikes now. It meets the JASO-MA spec required by Honda and is only around $21/gal at Wally World.
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I use the 10/40 Mobil 1 synthetic motorcycle oil , when cold the 10 is the same as the 10/30 but when hot you have safety build in.
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(11-17-2017, 02:26 PM)Flynrider_imp Wrote: SportsterDoc,
If you're riding in very high temps, I'd recommend switching to a synthetic. The combination of high temps and an air cooled engine can be very tough on dino oil. Add to that the shear factor from the oil circulating through the transmission gears and you're asking a lot from a multigrade dino oil.
Several years ago I started doing oil analysis on my bikes and found that summer time riding temps ( up to 115F) were having a bad effect on my favorite multigrade dino oil. The viscosity was down to a straight 20 weight after only 2000 miles.
I ended up switching both bikes to synthetic oil. Subsequent oil analysis showed that it was holding up well beyond 3500 miles of summer time riding. Well worth the extra few bucks!
I use Shell Rotella T6 (5w-40) in both bikes now. It meets the JASO-MA spec required by Honda and is only around $21/gal at Wally World.
My favorite also because it works and it's cheap.
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I thought I read somewhere that the Shell Rotella T is not a true synthetic (btw I used it in both my Yamaha FZ-1s for maybe 80,000 miles without issue)
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I'll be darned. The things you read on the interwebs.
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I have a really smart friend. His name is Google
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Seems to me the stuff I was using was a 15w40. Not sure if it was a t5 or t 6 but there does seem to be some discussion on the net that the formula was changed, along with a name change.
Google informs but it doesn't discuss lol
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I rode the Moto Guzzi this summer in temps past 115 (117-118F?) with Motoul 10W-60 synthetic.
I rode the Triumph two summers with temps past 115, with Castrol Power 1 20W/50 synthetic.
For the CB1100, figure one more oil change, probably February, with GN4 10W-30, then switch to 10W-40, probably in May/June.
The question is do I continue with Honda recommended GN4 or go to synthetic.
Since I have a proclivity to change oil frequently, switching to synthetic may be of less benefit.
If I do switch , then the question is Honda HP4 (MSRP $9.43/quart) or Castrol or maybe Motoul 4T 7100
Need to do more research, but I am presently inclined towards Castrol. Motoul is great oil, but VERY expensive.
Castrol is about $10.50 a quart at AutoZone or O'Reillys.
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